HILLAH, Iraq — The remains of what was once the greatest city in the world occupy a vast site on the bank of the Euphrates River.

Their roots go back 3,800 years to when the city of Babylon was the heart of a Mesopotamian empire, and the remnants include great slabs of stone that are said to be the remains of King Nebuchadnezzar’s castle. A giant stone lion guards one end of the fortifications, but the most stunning remnants were removed by European archaeologists in the early 20th century.

Now soldiers with the 172nd Infantry Brigade are exploring the ruins as part of a U.S.-Iraqi effort to preserve the ancient city and plan for the return of Western tourists.

Members of the brigade’s 2nd Battalion, 28th Infantry Regiment escorted a group of U.S. heritage tourism experts to the ruins last week for the first of several visits to develop a preservation and tourism plan for the area.

U.S. and coalition troops have been criticized in the past for damaging and contaminating artifacts. In a 2006 report, the head of the British Museum’s Near East department said that, among other things, military vehicles crushed a 2,600-year-old brick pavement, and sand and archeological fragments were used to fill military sandbags.

Now the rapidly improving security situation in surrounding Babil province has persuaded the U.S. State Department and the Iraqi State Board of Antiquities and Heritage to embark on the preservation project, dubbed the Future of Babylon Project.

The State Department and the World Monuments Fund have committed $700,000 to the project, which will see U.S. and Iraqi experts develop a plan to preserve the site and develop a local tourism industry, said Diane Siebrandt, the U.S. embassy’s cultural heritage officer.

The Babylon project is one of several that the State Department is involved in to conserve ancient sites in partnership with the Iraqi government, she said.

Two people with expertise developing tourism plans for historic sites in third-world nations, Gina Haney and Jeff Allen, have been employed by the State Department to run the U.S. side of the project. They visited the ruins for the first time last weekend.

Haney said the pair will involve the local community in the plan’s development, as they did with a similar project encouraging Western tourists to visit Ghana’s Gold Coast.

“You could throw money at it and do all this work, but unless you can create a sustainable situation, your opportunities for tourism will run out,” Allen said. “The idea is to develop something that is going to be here 30 to 40 years from now and has benefits for the local people. We don’t want something that will only benefit outsiders.”

The Iraqi government will be involved in the planning as well.

“If you have 200,000 people a year coming to this site, you will have people staying at hotels, visiting restaurants, buying souvenirs,” Allen said. “The site is in some ways a revenue generator for the local community.”

Babylon could be comparable to the Egyptian pyramids, which draw millions of tourists each year. But the area lacks the tourist infrastructure that has been built at sites such as the pyramids, he said.

“There is nothing for tourists here, but if you interpret and present it in the right way, you can spark interest,” he said.

Allen, who has experience designing walkways and signs for other heritage sites, said detailed planning won’t happen until authorities have worked out how best to preserve the ruins. The crumbling rocks of the original city are surrounded by more elaborate and modern fortifications, including a maze-like collection of interior walls built on top of genuine ruins during Saddam Hussein’s time.

“Some of the past restoration work hasn’t been very good,” he said. “Saddam was trying to inherit the power of the ancients and continue that legacy. His restoration methods helped reinforce that vision of himself, and he created a pattern of restoration and repair work that benefited a certain agenda.”

One of the 172nd soldiers who visited the ruins, 1st Lt. Bryan Kelso, 24, of Jacksonville, Fla., walked in wonder near the ancient stones.

“It’s amazing to be surrounded by this history. To think that we are standing where Alexander the Great has been,” he said, referring to the great Macedonian conqueror who died in Babylon. “Babylon is one of the oldest and first civilizations known to man. They created the wheel and the first calendars. Everybody coming here gets a sense of what this place really is and how it all traces back.”